padata: Generic parallelization/serialization interface

This patch introduces an interface to process data objects
in parallel. The parallelized objects return after serialization
in the same order as they were before the parallelization.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 88 insertions, 0 deletions

diff --git a/include/linux/padata.h b/include/linux/padata.h
new file mode 100644
index 000000000000..51611da9c498
--- /dev/null
+++ b/include/linux/padata.h
@@ -0,0 +1,88 @@
+/*
+ * padata.h - header for the padata parallelization interface
+ *
+ * Copyright (C) 2008, 2009 secunet Security Networks AG
+ * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef PADATA_H
+#define PADATA_H
+
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+struct padata_priv {
+        struct list_head        list;
+        struct parallel_data    *pd;
+        int                     cb_cpu;
+        int                     seq_nr;
+        int                     info;
+        void                    (*parallel)(struct padata_priv *padata);
+        void                    (*serial)(struct padata_priv *padata);
+};
+
+struct padata_list {
+        struct list_head        list;
+        spinlock_t              lock;
+};
+
+struct padata_queue {
+        struct padata_list      parallel;
+        struct padata_list      reorder;
+        struct padata_list      serial;
+        struct work_struct      pwork;
+        struct work_struct      swork;
+        struct parallel_data    *pd;
+        atomic_t                num_obj;
+        int                     cpu_index;
+};
+
+struct parallel_data {
+        struct padata_instance  *pinst;
+        struct padata_queue     *queue;
+        atomic_t                seq_nr;
+        atomic_t                reorder_objects;
+        atomic_t                refcnt;
+        unsigned int            max_seq_nr;
+        cpumask_var_t           cpumask;
+        spinlock_t              lock;
+};
+
+struct padata_instance {
+        struct notifier_block   cpu_notifier;
+        struct workqueue_struct *wq;
+        struct parallel_data    *pd;
+        cpumask_var_t           cpumask;
+        struct mutex            lock;
+        u8                      flags;
+#define PADATA_INIT             1
+#define PADATA_RESET            2
+};
+
+extern struct padata_instance *padata_alloc(const struct cpumask *cpumask,
+                                            struct workqueue_struct *wq);
+extern void padata_free(struct padata_instance *pinst);
+extern int padata_do_parallel(struct padata_instance *pinst,
+                              struct padata_priv *padata, int cb_cpu);
+extern void padata_do_serial(struct padata_priv *padata);
+extern int padata_set_cpumask(struct padata_instance *pinst,
+                              cpumask_var_t cpumask);
+extern int padata_add_cpu(struct padata_instance *pinst, int cpu);
+extern int padata_remove_cpu(struct padata_instance *pinst, int cpu);
+extern void padata_start(struct padata_instance *pinst);
+extern void padata_stop(struct padata_instance *pinst);
+#endif